Wash-pipe anchor



April 25, 1939. l.. A. LAYNE ET AL WASH-PIPE ANCHOR I Filed Nov. l9. 1935 INVENTOR. A YN E TTORNEY Jlvllllll. L

Patented Apr. 25, 1939 UNITED STATES WASHfPIPE ANCHOR.

Leslie A. Layne and Louis C.- Mundt, Houston, Tex.; said Mundt assignor to said Layne Appn'canon memberJ 19, 1935, serial No. 50,524 4 claims. (ci. 16s-1o) The invention relates to an anchor for the wash pipe which is used in completing a well when it is desired to wash the drilling mud or other foreign materials from the well screen and the face of the formation as the well is completed.

the producing formation so that the well may be completed in safety. When the screen has been set, however, it is then desirable to wash out this column of 'mud and thev face of the producing formation so as to increase the produc- 0 tion. It is usual to run the strainer or screen into the well while it is iilledl with this mud formation, and it is, of course, necessary then to wash the screen thoroughly so that it will not be clogged with this mud. In order to do vthis 25 it is desirable to prevent any excess pressure on the inside of the screen whichwould have a tendency to cause a flow of liquid from the in-` sideito the outside of the screen.

With the foregoing operations' in ."view, it is 0 one oi' the' objects of the invention to provide a combination seal and anchor for the wash pipe during the washing operation so that no presslre will occur on the fluid which is present inside of the screen and liner.

y, Another object of the invention is to providel ran enlarged sealing head for the washpipe so that the flow o! washing fluid therethrough will exert a downward thrust on the wash pipe and l hold it in sea-ling position so that the washing 0 uid will be forced out at the lower end of the screen rather than leak in'to the a'rea inside of the screen. l y

Another object of the invention is to provide a combination wash line and setting tool assem- 45 bly whereby a seal will be maintained to prevent around the setting tool.

Another object of the invention is to provide a seal at the lower end of the 'wash line so that all of the washing liquid will be discharged outside of lthe screen.

- Still another object of the invention is to pro- -vide a method of setting screen so that vthe screen will not become clogged with mud, which includes the steps of lling the screen with water as it is lowered into the column of mud in the well and then maintaining this water in the screen duringv the well washing operation, so that as a last step of completing the 'ell the water may be forced from the screen t purge it of any small accumulations of mud.

A still further object oi' the invention is to trap a body of oil or water inthe screen during the washing operation.

Other and further objects of the invention will be readilyapparent when the following description is considered in connection with the accompanying drawing wherein:

a Figure 1 is a vertical sectional view of the well bottom with the apparatus in position to effect the washing operation.

Figure 2 is a sectional view of the wash line =head winch is used to form a seal and anchor the wash pipe.

Thewell bore is indicated generally at 2 and the weil casing is iindicated at 3, whilethe producing formation is illustrated rbelow the end of the casing at l.

The apparatus for washing the well is shown as having been lowered through the casing 3 to v an elevation opposite the producing formation 4.

This apparatus includes the set or guideshoe 5, which usually carries a back pressure valve 6 and the wash line seat 1. The screen 8 is connected above this shoe 5 and depending upon the length of; the screen 8 the wash line 9 may or may not b'fconnected in sections as the screen is lowered into l'the well at the surface.

It is the usual practice in lowering a pipe into the well to fill the pipe with mud or water so and followhig this the packer l2 will be next` assembled. It is to be understood that in some instances as much as or 200 feet of screen may be placedin thev well and the liner Il may also have considerable lengthso that' this entire 4along with the other parts, it will then extend upwardly through the setting tool as at 2l.

'I'he wash line drive connection 2i is then positioned in place on the head 22 connected to the wash pipe, and nally the setting string 23 is connected and the entire assembly is then lowered into the ywell by adding sections of pipe to the setting string 23, which may be a string oi drill pipe, a special string oi." setting pipe, or it may l be the tubing which is to be permanently located in the well, various practices being used in the iield depending upon well conditions and the ideas of various; production superintendents.

With the parts in the position shown in Figure l the assembly is lowered t'o the elevation there shown, it being understood that either water or mud may be added in the .pipe 23 as the assembly is lowered so as to balance the pressure inside and outside of the screen.

4When the apparatus is iinally lowered and the shoe 5 contacts the bottom .of the well, then it is raised slightly and a circulation of water is begun downwardly .through the pipe 23 until pressure causes the opening of the back pressure lvalve 6 so that the water will flow outwardly into the well bore as indicated by the arrow 25. This water dilutes the, mud which is present in well bore Ill and circulation flows upwardly through the casing at 26, so that the returns or discharge from the well can be observed and in this manner the operator knows when the mud has been removed. y

Needless to say, in some instances considerable pressure is applied to the stream of water because of the enormous weight of the mud, it being understood that in some instances mud heaviers are applied to the drilling mud and such muds sometines have a specific gravity as great as 2. This pressure, of course, tends to leak into that area inside of the screen 5 and it'is desirable, as previously pointed out, to prevent any excessive pressure occurring on the inside of the screen. If the screen is filled with mud and a greater pressure is exerted on the inside thereof. it has been found in practice that this pressure tends to force the water from the mud and in this manner the mud is concentrated so that it deposits on the inside oi the screen, which is.` oi' course, objectionable. In other words, when pressure ls applied to the mud it has been found that the water is squeezed out through .the screen. To

avoid this feature the present invention contemplates providing complete seals for this area inside of the screen. The first seal is provided by a packing 30, which is positioned below" the coupling 3l on the lower end of the wash line, and this packing is arranged to abut against the seat 1 when the wash line 9 is in'positionand preventing any leakage upwardly into the screen around the wash pipe.

The next seal to prevent the entrance of liquid around the inside of the liner is shown at 35 and constitutes a packer or seal 36 which is carried by the body 31 of the setting tool I4. This seal 36 is in the form of a ring which is held in posij-tion -h'yQretainer ring 33 and is of a size to ilt closely against the inside oi the liner II. Thus.

` pipe 23.

if vthere is any leakage under the shoulder I6 of the setting tool, it will be sealed of! by this packing 36.

An additional seal 40 is shown on the head of the wash pipe in the form o! a piston or plunger, which is seen in section in Figure 2. This plunger presents a surface`4I to the fluid beingforced downwardly through the wash pipe, and in this manner the seal is expanded against the inside of the pipe 23 so that there can be no leakage ot this wash pipe into the setting tool or the inside of the screen 3.

The particular construction of this plunger head causes it to serve as anyanchor to hold the wash pipe in position during all of the operations, and this anchor includes the metal body 45 which is threaded at 46 for attachment to the wash line 9. The body 45 is undercut at 41 and' provided with a shoulder at 46 so' that the rubber material 49 may be molded thereon/.and will be ilrmly anchored in position. The upper end of the body is recessed at 50 and the rubber material is carried from the inside edge to Iorm a retainer collar 5I. In this manner all of the pressure is exerted on the face 4I and tends to move the lip 52 outwardly to form a seal with the inside of the Because of the high velocity of the wash liquid this seal is most important and for this reason is formed in the manner shown.

When considerable pressure is exerted in the wash line 3 there will ot course be a reaction to be absorbed by the wash line the same as the reaction in a high pressure rire hosenozzle. Thus there may be a tendency for the wash pipe to iloat out or move up in the assembly. Such movement would of course release theseal at 30.`

With the head 40 however, there will be a preponderance of downward pressure to anchor the wash pipe.

It seems obvious from the foregoing description thatany body ol liquid which is placed inside of the screen 8 as it is lowered into the well will be sealedinto position against any excessive pressure other than a balancing of the pressure on the inside and outside of the screen through the screen openings. In other words, this body oi liquid will be held dormant during the entire operation because of the seals above described. The washing operation is then completed so that all o! the foreign matter is washed from the outside of the well and the Aoperator is enabled to ascertain this fact because of the clear water or oil running from the well depending upon which liquid is used for the washing operation.

'I'he next step is then to set the packer I2 to form a seal with the inside of the casing 3. This closes the outside passage and of course releases the setting tool I4 from its threaded connection at 'I5. The setting tool is then raised so that the coupling 22 abuts against the drive bushing 2| and the wash line 9 is then pulled from the seat 1. Ifthe inside of the screen 8 has been lled with mud, then the washing operation can be continued by pumping liquid down through the wash line and upwardly through the liner II until the inside of the screen is also washed. On the other hand, if the screen I has been lled with water, only suillcient washing liquid may be circulated to cause a slight discharge of the water through the screen to purge it of any sediment .which may have laccumulated therein.

If the string of pipe 23 is the tubing. then the production is permitted to go in through the wash line and upwardly through the tubing with the setting tool and wash line remaining in the well.

Under these conditions the pressure of the column inside of the tubing 23 is exerted on the surface 4| and tends to anchor the wash pipe'in position so that the flow of oil or gas upwardly through the wash line cannot carry the wash line upwardly. Instances where the wash line has been lifted upwardly have occurred. It is therefore desirable to anchor the wash line during this operation as above described.

If the string of pipe 23 is a drill stem, then the entire setting tool and wash line along with the drill stem are removed from the well and the tubing is run into position.

Another method which may be followed in bringing in the well with the present apparatus is a method where excessive formation pressures are encountered and it is dangerous to wash the well until a seal has been permanently arranged around the tubing or wash line at the surface.

When this type of well completion is desired the body of water will be deposited in the screen and part way up the wash line or tubing 23 as well, so that there is present in the assembly as Iit is lowered into the well a body of water which is estimated as at least equal to the volume of the Well bore below the area where the packer I2 is to be set.

The assembly is then lowered into the position shown in Fig. 1 of the drawing and the pump is operated a predetermined number of strokes so as to discharge the volume of water in the setting string 23 downwardly through the pipe 9 and outwardly in the well bore so as to displace the mud in the bore below the packer I2 outside of the screen. y

When this displacement has occurred it seems obvious that the mud has been removed from the producing formation but the excessive weight of the heavy `mud in the well bore still overcomes the formation pressure so that there is little or no danger of a blowout.'

The next step then is to set the packer I2 to form a seal around the outside of the' liner and screen. When the packer has thus been set the setting string 23 and the setting tool will be lraised ,suiliciently to withdraw the wash line 9 from its seat and raise it to the desired elevation, preferably Just above or below the top of the liner l1. Then a permanent seal may be arranged at the casing head by hanging the setting string, or tubing as it will probably be called in this instance, in its permanent position. The well head is closed in when all these seals have been made, and the only remaining step is to circulate water or oil downwardly through the tubing so as to gradually displace the column of position 'and to substantially form a plug in mud in the well casing. The fact that the packer l2 is set and prevents upward flow on the outside o! the screen causes the slug of water inside and outside of the screen to be trapped in this the well, so that it is not materially disturbed by the subsequent circulation. I

As the mud is gradually reduced the pressure on the formation becomes balanced, and by careful inspection of the returns from the discharge line, the operator is enabled to determine when all of the mud has been removed or when the pressures are becoming unbalanced by the pres` ence of oil and gas in the water or the presence of gas in the oil if oil is used for washing. If the formation has sufficient pressure the well will then come in of its own accord as the pressure on the formation is reduced. If not, when the returns have cleared up a swab can be run through the tubing and production started in this manner. In either instance, the completion of the well has occurred under very safe conditions, and the screen is free o f mud and very satisfactory results have been obtained by completing the well in this manner.

The invention contemplates broadly the trapping of a body of liquid in the well screen to prevent pressure from being applied thereto and to form a seal about the screen in combination with clogged with mud, comprising'the steps of depositin'g a body oi liquid in the screen assembly as it is lowered into the well bore, trapping the liquid in the assembly, sealing the liquid against the inilow of liquid from the well, washing the mud from the we llwhile the liquidA is trapped in the screen assembly, and releasing the seals and wash pipe.

3.. In combination with a strainer assembly, a wash pipe, a seat therefor on said assembly to slidably receive said pipe, a seal about said pipe at said seat, and means to hold down said washpipe'tomaintain said seal, including a sealing tween said pipe and the strainer whereby the strainer is closed to the inlet or discharge of LESLIE A. LAYNE. LOUIS C. MUNDT.

. uld at its ends. 

